A new study published in the British Journal of Cancer has shown that cervical screening has an even larger impact on preventing death from cervical cancer than it has on preventing the incidence of cancer itself; if all eligible women attended screening regularly, 83% of cervical cancer deaths could be prevented, in comparison with 70% of cervical cancer deaths prevented from current screening.
It is well established that screening can reduce the incidence of cervical cancer. The National Health Service (NHS) Cervical Screening Programme aims to prevent women from developing and dying from cervical cancer, and women between the ages of 25-64 are invited for cervical screening (between every 3-5 years, depending on age). A cervical cancer audit was established in the early 1990s to evaluate and monitor the effectiveness of the NHS Cervical Screening Programme in preventing cervical cancer development and death. While the effect of the screening programme on the occurrence of cervical cancer has been well researched, the impact of regular screening on deaths resulting from cervical cancer is unknown.
A group of researchers examined the potential preventive significance of regular screening on identification and deaths resulting from cervical cancer. They used cervical screening information from a population-based case-control study of cervical cancer incidence in England that is estimated to include roughly 90% of all cervical cancers. They examined the screening history of more than 11, 619 women, between 25 and 70 years of age in England diagnosed with cervical cancer between 2007-2013, and age-matched two controls who did not have cervical cancer to each case (i.e., someone diagnosed with cervical cancer). The researchers compared the probability of developing cervical cancer for women who were screened with women not screened throughout the last 15 years. Finally, they evaluated the extent of deaths resulting from cervical cancer within 5 years of being diagnosed.
The findings, published in the British Journal of Cancer, suggests that there is a stronger link between screening for cervical cancer and decreased incidence in more advanced stages of cervical cancers, and screening is more effective in preventing death from cervical cancer compared to preventing cancer itself. The researchers found that among women between 35 and 64 years of age, regular screening is related to a 67% decreased chance of being diagnosed with stage 1A cancer and a 95% decrease in stage 3 or cervical cancer. Moreover, they estimated more than twice the number of cancers being diagnosed in women between 25 and 79 years old in the absence of screening. Among all eligible women who were screened on a regular basis, it is estimated that around a third less cancers would occur.
Furthermore, while screening is estimated at the present time to prevent 70% of deaths due to cervical cancer (all ages) in England, 83% of deaths may be prevented (i.e., half of all deaths occurring at the present time could be prevented) if everyone regularly attended screening. Further, it is estimated that in the absence of screening, there would be an added 1827 deaths annually due to cervical cancer, and if screening was attended regularly by everyone between 35-64 years old, an additional 347 deaths per year could be prevented. The study further revealed that women aged 50 to 64 would be more greatly impacted by screening practices; in the absence of screening among women between 35 and 49 years old, there would be a four-times greater possibility for cervical cancer deaths, and among those between 50 and 64, there would be five times higher cervical cancer deaths. Finally, among all women screened regularly, death rates would be lower than half of what it is at the present time for women between 35 and 49 years old at diagnosis and decreased by two-thirds for women between 50 and 64 years old.
The overall findings suggest that while thousands of cervical cancers are currently being prevented by screening each year, even a greater number of cancers could be prevented and lives saved if uptake of screening is further improved and all women who are eligible attended screening. These findings are promising and should be utilized to promote, among policy makers, the implementation of screening programs in regions not yet protected and, in women, regular attendance to screening.
Written By: Nigar Celep, BASc